Ex situ diesel contaminated soil washing with mechanical methods

Soil washing is a dynamic, physical process that cleans contaminated soil through transfer of the contaminant into a liquid stream. Three mechanical washing methods, i.e. jet reactor, attrition and ultrasonic washing were evaluated on a laboratory scale. The operating parameters for each washing process were investigated in detail and mechanisms are proposed for the observed effects. In a techno—economic comparison of the three methods, the jet reactor performed best, followed by ultrasonic and attrition washing. Experimental results suggested that a combination of the three washing techniques could yield residual diesel levels of less than 1000 mg/l for sand particles with an approximate size of 0.1 mm and an initial diesel content of 5%.